See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/263934329 The Potential Therapeutic Effects of THC on Alzheimer's Disease ARTICLE in JOURNAL OF ALZHEIMER'S DISEASE: JAD · JULY 2014 Impact Factor: 4.15 · DOI: 10.3233/JAD-140093 · Source: PubMed CITATIONS 5 READS 1,203 9 AUTHORS, INCLUDING: Yaqiong Li University of South Florida 15 PUBLICATIONS 79 CITATIONS SEE PROFILE Xiaoyang Lin University of South Florida 35 PUBLICATIONS 724 CITATIONS SEE PROFILE Neel Nabar National Institute of Allergy and Infectious … 8 PUBLICATIONS 28 CITATIONS SEE PROFILE Jianfeng Cai University of South Florida 70 PUBLICATIONS 835 CITATIONS SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. Available from: Chuanhai Cao Retrieved on: 28 December 2015
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Journal of Alzheimer’s Disease xx (20xx) x–xxDOI 10.3233/JAD-140093IOS Press
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The Potential Therapeutic Effects of THC onAlzheimer’s Disease
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Chuanhai Caoa,b,∗, Yaqiong Lic, Hui Liua,b, Ge Baic, Jonathan Maylb, Xiaoyang Lina,b,Kyle Sutherlandd, Neel Nabare and Jianfeng Caic,∗
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aCollege of Pharmacy, University of South Florida, Tampa FL, USA5
bUSF-Health Byrd Alzheimer’s Institute, University of South Florida, Tampa FL, USA6
cDepartment of Chemistry, University of South Florida, Tampa FL, USA7
dCollege of Medicine, University of South Florida, Tampa FL, USA8
eThomas Jefferson University, Philadelphia, PA, USA9
Accepted 29 April 2014
Abstract. The purpose of this study was to investigate the potential therapeutic qualities of �9-tetrahydrocannabinol (THC)with respect to slowing or halting the hallmark characteristics of Alzheimer’s disease. N2a-variant amyloid-� protein precursor(A�PP) cells were incubated with THC and assayed for amyloid-� (A�) levels at the 6-, 24-, and 48-hour time marks. THC wasalso tested for synergy with caffeine, in respect to the reduction of the A� level in N2a/A�PPswe cells. THC was also testedto determine if multiple treatments were beneficial. The MTT assay was performed to test the toxicity of THC. Thioflavin Tassays and western blots were performed to test the direct anti-A� aggregation significance of THC. Lastly, THC was testedto determine its effects on glycogen synthase kinase-3� (GSK-3�) and related signaling pathways. From the results, we havediscovered THC to be effective at lowering A� levels in N2a/A�PPswe cells at extremely low concentrations in a dose-dependentmanner. However, no additive effect was found by combining caffeine and THC together. We did discover that THC directlyinteracts with A� peptide, thereby inhibiting aggregation. Furthermore, THC was effective at lowering both total GSK-3� levelsand phosphorylated GSK-3� in a dose-dependent manner at low concentrations. At the treatment concentrations, no toxicity wasobserved and the CB1 receptor was not significantly upregulated. Additionally, low doses of THC can enhance mitochondriafunction and does not inhibit melatonin’s enhancement of mitochondria function. These sets of data strongly suggest that THCcould be a potential therapeutic treatment option for Alzheimer’s disease through multiple functions and pathways.
In 2011 alone, 15 million family members have pro-27
vided more than 17.4 billion hours of care to diagnosed28
Alzheimer’s disease (AD) patients. That care translates29
into more than $210 billion of AD-related services [1].30
This disease translates into an enormous burden on31
caregivers, as well as the health care system, both med-32
∗Correspondence to: Chuanhai Cao, PhD, College of Pharmacy,University of South Florida, USF-Health Byrd Alzheimer’s Insti-tute, 4001 E. Fletcher Avenue, Tampa, FL 33613, USA. Tel.: +1813 3960742; Email: [email protected] and Jianfeng Cai, PhD,Department of Chemistry, University of South Florida, Tampa, FL33620, USA. E-mail: [email protected].
ically and economically. To date, there have been no 33
effective treatments developed to cure or delay the pro- 34
gression of AD [2, 3]. By 2050, an estimated 11 to 16 35
million Americans will be living with the disease [1, 36
4]. 37
AD pathology can be divided into two cate- 38
gories, familial inherited AD and sporadic AD. The 39
histopathologies of early onset familial AD and late 40
onset sporadic AD are indistinguishable. Both forms of 41
AD are characterized by extracellular amyloid-� (A�) 42
peptide, and by amyloid plaques and tau-containing 43
neurofibrillary tangles [3]. The misfolded structure of 44
the A� peptides generates a characteristic tendency 45
for their aggregation [5]. It has long been believed 46
ber, Glasgow, UK). Detail method is published in 291
Dragicevic et al. [38]. 292
Statistical analysis and graphs 293
All data were analyzed with one-way ANOVA and 294
post hoc analysis was conducted with Turkey’s group 295
analysis and p < 0.05 was considered as statistical sig- 296
nificance (GraphPad 6.0). All graphs were graphed 297
with GraphPad 6.0 software. 298
RESULTS 299
THC can decrease Aβ level in N2a/AβPPswe 300
ELISA assay was performed for A�40 levels in 301
N2a/A�PPswe cells 6 hours after cells were treated 302
at different concentrations individually with THC, and 303
caffeine—a reported compound to lower serum A�40 304
levels in a mouse model [39]—showed a significant 305
reduction in A�40 levels of THC and caffeine ver- 306
sus the control (Fig. 1A). However, 24 hours after 307
treatment of N2a/A�PPswe cells, A�40 concentra- 308
tions were measured again in the THC treated cells 309
versus the control. An increasing difference in A�40 310
concentrations were noted in both THC treated cells 311
and caffeine treated cells in a dose-dependent man- 312
ner (Fig. 1B). The assay was performed again, 48 313
hours after treatment of N2a/A�PPswe cells with THC 314
versus the control at each concentration of the drugs 315
originally used. THC-treated N2a/A�PPswe cells sig- 316
nificantly differed more in A�40 concentrations versus 317
the control then at the 6- and 24-hour time point. The 318
significant difference was conserved and greater over 319
each increasing dose of THC and caffeine adminis- 320
tered versus the control (Fig. 1C). These data suggest 321
THC’s and caffeine’s inherent anti-A�40 properties are 322
time and dose dependent in N2a/A�PPswe cell mod- 323
els. This data also reveals that THC may delay of halt 324
the progression of AD by inhibiting the production of 325
A�40 peptide in the central nervous system. 326
Synergy between THC and caffeine on Aβ40 327
concentration in N2a/AβPPswe cells 328
THC and caffeine were assayed for a synergistic 329
effect on A�40 concentration in N2a/A�PPswe cells 330
(Fig. 2). However, no synergistic properties of THC 331
and caffeine are seen as there is no significant differ- 332
ence in the concentration of A�40 in N2a/A�PPswe 333
cells solely treated with THC as compared to cells 334
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Fig. 1. (A) A�40 (pg/ml) in vitro measured 6 hours from incubation in N2a/A�PPswe cells. Three groups of cells were assayed: 1) thosethat were not treated with THC; 2) those that were treated with THC; and 3) those that were treated with caffeine. Treatment in both the THCgroup and in the caffeine group resulted in a dose-dependent decrease in A�40 concentration after 6 hours. There are no significant differencesamong all groups (p > 0.05). The concentrations of THC from A to F are 0 nM, 0.25 nM, 2.5 nM, 25 nM, 250 nM, and 2500 nM respectively,and concentrations of caffeine from A to F are 0 �M, 0.625 �M, 1.25 �M, 2.5 �M, 5 �M, and 10 �M, respectively, (B) A�40 (pg/ml) in vitromeasured 24 hours from incubation in N2a/A�PPswe cells. A dose-dependent decrease in concentration of A�40 was still observed. THC: A,B, C, versus F are p < 0.05 and all other groups in comparison are p > 0.05. Caffeine: A versus B, B versus E, and all other groups versus F arep < 0.05. The concentrations of THC from A to F are 0, 0.25 nM, 2.5 nM, 25 nM, 250 nM, and 2500 nM, respectively, and concentrations ofcaffeine from A to F are 0, 0.625 �M, 1.25 �M, 2.5 �M, 5 �M, and 10 �M, respectively, (C) A�40 (pg/ml) in vitro measured 48 hours fromincubation in N2a/A�PPswe cells. A dose-dependent decrease in A�40 (pg/ml) in conserved. THC groups: p > 0.05 for A versus B, and all othergroups are p < 0.05. Caffeine groups: p < 0.05 for B versus D, and all other comparisons between groups are p > 0.05. The concentrations of THCfrom A to F are 0, 0.25 nM, 2.5 nM, 25 nM, 250 nM, and 2500 nM, respectively, and concentrations of caffeine from A to F are 0, 0.625 �M,1.25 �M, 2.5 �M, 5 �M, and 10 �M, respectively.
treated with 2.5 �M caffeine and THC at various335
concentrations.336
Repeated treatment can continuously decrease Aβ337
production338
Our data also illustrates N2a/A�PPswe cells treated339
with THC twice, 24 hours apart from each treatment,340
showed a significant decrease in A�40 concentra-341
tion compared to cells treated once (Fig. 3A). While342
the decrease in A�40 expression is not observed343
at concentration close to 10 �M, they are seen at344
25 �M and greater suggesting multiple treatments345
may be efficacious in reducing A�40 concentration in346
N2a/A�PPswe cells and animal models.347
Cell toxicity detection of THC on N2a/AβPPswe348
cells349
THC was also measured for toxicity versus the caf-350
feine and the untreated N2a/A�PPswe cells, which351
served as the control. The MTT assay showed no352
significant difference from the control for toxicity as353
compared to each concentration of THC and caffeine354
administer suggesting THC and caffeine lack toxicity355
to the cells at each concentration assayed (Fig. 3B).356
THC can inhibit Aβ40 aggregation as shown by357
ThT assay and western blot358
The ThT assay was to exhibit the direct interaction359
THC has with A� demonstrates that as the concen-360
4000
5000
6000
7000 Caffeine THCTHC+CC+THC
A=caffeine at 10, 5,2.5, 1.25, 0.625, 0 µM;B=THC at 2.5 µM, 250 nM, 25 nM, 2.5 nM , 250 pM and 0pM;C=caffeine at 2.5 µM and THC at concentration as B;D=THC at 25 nM and Caffeine concentration as A.
THC and Caffeine synergism on Aβ40 level(pg/ml)
drug concentrations
A β40
(pg/
ml)
Fig. 2. A�40 (pg/ml) concentration in N2a/A�PPswe cells at vari-ous drug concentrations among groups. Treatment with both THCand caffeine resulted in a dose-dependent decrease in A�40 concen-tration. However, no synergistic effect was observed.
tration of THC added to the assay was increased, the 361
intensity of fluorescence in A� decreased. This data 362
suggests that A� peptide directly binds to THC and 363
prevents the uptake of fluorescence (Fig. 4A). More- 364
over, our lab performed an additional ELISA assay to 365
confirm that the interaction of the A� peptide with THC 366
did not shield amino acids 1–10, the major B-cell epi- 367
tope [40] (Fig. 4B). There is no significant difference in 368
absorbance at each concentration of THC, indicating 369
that at each concentration of THC the A� antibodies 370
were able to bind with equal distribution and affinity. 371
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0uM 6.25uM 12.5uM 25uM 50uM 100uM0
100
200
300
400THC treated twiceTHC treated once
Drug Conc.
Abe
ta40
(pg/
ml)
(A)
(B)
Fig. 3. (A) A�40 (pg/ml) concentration N2a/A�PPswe cells treated with THC, as well as the A�40 (pg/ml) concentration of N2a/A�PPswecells treated with THC twice, 24 hours apart. The number of treatments has shown to decrease the concentration of A�40 (pg/ml), (B) Thisshows the data obtained from the reduction of MTT at different concentrations of THC versus the different concentration of caffeine. UntreatedN2a/A�PPswe cells were also assayed to compare with the MTT reduction of N2a/A�PPswe cells treated with THC and caffeine at differentconcentrations.
0uM 250pM 2.5nM 25nM 0.25uM 2.5uM
0.5
1.0
1.5
2.0
Possibility of THC interfering Aββ-specific Ab.binding to Aβ 40 protein
Abeat40 coated with 250pg/ml
THC Concentration
OD
450±
SD(B)
(A)(A)
Fig. 4. (A) ThT assay measuring the fluorescence of Thioflavin T which binds to �-sheet structure of A� aggregation. With addition of THC,dose-dependent decreases in intensity of fluorescence indicates THC directly interferes with the binding of ThT to A� peptide. (B) THC incubatedwith A� peptide to determine the occurrence of THC interference with the major B cell epitope. No identified interference was observed at eachincreasing concentration of THC.
(A)(B)
Fig. 5. (A) Polyacrylamide gel from a western blot indicating the concentration of aggregated A� peptide with and without the treatment ofTHC at various concentrations. Groups: 1: Aggregation control; 2: THC 100 nM; 3. THC 10 nM; 4: THC 1 nM, (B) THC anti-aggregation assaygel quantification indicating the relative percent monomeric A�.
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Treatment
Aβ4
0(pg
/ml)
Fig. 6. ELISA assay elucidating a possible mechanism throughwhich THC functions to decrease the synthesis of A� inN2a/A�PPswe cells. A� level increases at 36 hours and reachesits peak level at 48 hours. Follow this mark; it then starts decreasingat 60 hours. The drug treatment benefit time is seen at 36 hours andlast to 48 hours (the best window time). THC can significantly lowerA� and this function can be partially blocked by CB1 antagonistRimon at 10−4 M. However, inhibition function is lost at 10−7 M.
Therefore, we can postulate that THC’s direct interac-372
tion with the A� peptide will not dampen an immune373
response to clear the A� peptide.374
Further analysis with western blot was performed375
measuring the anti-aggregation properties of THC with376
A� peptide. At each increasing concentration of THC,377
a higher relative % of A� monomer was observed378
correlating with a lower intensity of aggregated A�379
peptide. This data suggests the direct interaction of380
THC with A� peptide and its ability to bind to the381
peptide and inhibit aggregation (Fig. 5A,B).382
CB1 receptor antagonist can partially rescue Aβ383
level inhibited by THC384
An ELISA was performed to determine the mech-385
anism of THC in supporting the reduction of A� in386
N2a/A�PPswe cells. A known inhibitor of the CB1387
receptor, rimonabant, was mixed with THC at differ-388
ent concentrations. Untreated N2a/A�PPswe cell A�389
concentrations were used as a control. It was noted that390
a dose dependent increase in A� was observed as the391
concentration of the inhibitor was increased. A time392
dependent effect of the inhibitor was also witnessed as393
the assay was repeated at the 12-, 36-, 48-, 60-, and394
72-hour mark (Fig. 6). Due to increasing A� concen-395
trations as the inhibitor concentration is increased, this396
suggests that THC partially functions through the CB1397
receptor to mediate the synthesis of A�. The RT-PCR398
results for CB1 receptor expression level showed that399
there is no significant upregulation by THC to CB1 400
receptor (data not shown). 401
THC can inhibit total GSK-3β and phosphorylated 402
GSK-3β (pGSK-3β) production 403
The western blot assay performed to examine the 404
effect of THC on GSK-3� exhibits a dose-dependent 405
decrease in GSK-3�. �-actin, a housekeeping gene, 406
was used as a control to indicate that GSK-3� was 407
expressed at a constant rate and that the changes in 408
intensity are not related to the change in expression 409
amount. As shown in Fig. 7A-D, this data suggests that 410
THC is efficacious in modulating and ameliorating the 411
expression of GSK-3� and could decrease neuronal 412
apoptosis by down regulating GSK-3�. 413
THC can inhibit phosphorylated (pTau) 414
production, but not affect AβPP production 415
We detected pTau and A�PP levels among different 416
treatment conditions. THC can lower pTau expression 417
level with dose-dependent administration, but we did 418
not see the differences in A�PP levels detected with 419
6E10 antibody (Fig. 8A-F). 420
THC can enhance mitochondrial function but will 421
not interfere with melatonin’s enhancement of the 422
mitochondria 423
Isolated mitochondria from N2a/A�PPswe cells 424
showed higher oxygen utilization when treated with 425
THC. When combined with melatonin, the function of 426
the mitochondria is not altered (Fig. 9A, B). 427
DISCUSSION 428
Advances in therapeutics to prevent AD, or delay the 429
progression, are currently being made. Recent research 430
has shown caffeine and coffee are effective in limiting 431
cognitive impairment and AD pathology in the trans- 432
genic mouse model by lowering brain A� levels, which 433
are thought to be central to the pathogenesis of AD [41]. 434
Similarly, the current study shows the in vitro anti-A� 435
activity of caffeine, and of another naturally occurring 436
compound, THC. 437
N2a/A�PPswe cells were incubated separately with 438
various concentrations of caffeine, melatonin, and 439
THC. The relative anti-A� effect of THC was observed 440
to increase in a time dependent manner. A dose- 441
dependent decrease in A� concentration was noticed 442
at lower concentrations of THC, as compared to caf- 443
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50
37
25 ββ -actin GSK 3β
(A) (B)
(C)
(D)
Fig. 7. (A) A western blot performed to determine the effects of THC on GSK-3� in N2a/A�PPswe. �-actin was used as a control to indicatethat the expression rate was constant. The left indicator is molecular weight. Lane 1, 2, and 3 are �-actin level and lane 4, 5, and 6 are GSK-3�expression. 1 and 4 are cell controls, 2 and 5 are cells treated with 2.5 nM THC, and lane 3 and 6 are cells treated with 0.25 nM THC. THC caninhibit GSK-3� level at 2.4 nM concentration, (B) Graph representing the expression decrease in GSK-3� in a dose-dependent manner by using�-actin to obtain a value for the ratio of expressed GSK-3�. As shown in the bar graph, the total GSK-3� decrease after using �-actin standardizedprotein loading, (C) GSK-3� expression in N2a/A�PPswe treated with different drugs: Cells were plated in 6 well plate for overnight and thendrugs were added into each designated wells in duplicate. Cells were lysed after 36 hours incubation. Proteins were loaded onto SDS-pagegel and then blotted with each antibody after transfer onto PVDF membrane. Groups are: CTRL, Control; M1T2, 10−5 M Melatonin + 2.5nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2, THC 2.5 nM; T3, THC 0.25 nM, (D) Expression of pGSK-3�following melatonin and THC treatment in N2a/A�PPswe cells. *The same batch protein samples were used in this test as in Fig. 7C. Bandswere quantified. One-way ANOVA was applied to the data. p < 0.05 when compared with control group. **p < 0.01 when compared with controlgroup. Groups are: Ctrl, Control; M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2,THC 2.5 nM; T3, THC 0.25 nM.
feine. Further evidence shows that N2a/A�PPswe444
cells, treated twice with THC, show an even greater445
reduction in A� levels at slightly higher concentra-446
tions. Although it might have been predicted that447
caffeine and THC may function in a synergistic effect448
to reduce the A� load in N2a/A�PPswe cells, no syn-449
ergy was observed.450
The MTT assay confirmed that cells treated at effi- 451
cacious concentration of THC showed no toxicity, 452
suggesting such a treatment to be safe and effective 453
for further experimentation in the AD animal model. 454
However, valid arguments have transpired in recent 455
times regarding the concern for acute and long-term 456
memory impairment with the use of THC. It has been 457
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(A)(B)
(C)
(D) (E) (F)
Fig. 8. (A) A�PP expression in N2a/A�PPswe treated with different drugs. The sample protein samples as in Fig. 7C were used for western blotting assay. 6E10 anti-A� antibody was used todetect A�PP and �-Actin was detected as protein loading control. Groups are: CTRL, Control; M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25nM; T2, THC 2.5 nM; T3, THC 0.25 nM, (B) Quantification result of A�PP in western blotting: We used quantification method to further compare the differences among drug treatment to A�PPlevel. There are no statistical significant differences among all treatment (p > 0.05). This data indicates that THC did not change A�PP expression level. Groups are: Ctrl, Control; M1T2, 10−5 MMelatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2, THC 2.5 nM; T3, THC 0.25 nM, (C) Tau expression in N2a/A�PPswe treated with different drugs. Thesample protein samples as in Fig. 7C were used for western blotting assay. Anti-Tau and pTau antibodies were used to detect A�PP and �-Actin was detected as protein loading control. Groupsare: CTRL, Control; M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2, THC 2.5 nM; T3, THC 0.25 nM, (D) No significant difference ofpTau expression shown among six groups in N2a/A�PPswe cells. THC treatment has no function to pTau expression. Groups are: Ctrl, Control; M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2,10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2, THC 2.5 nM; T3, THC 0.25 nM, (E) Expression of pTau/Tau following melatonin and THC treatment in N2a/A�PPswe cells. +p < 0.05when compared with THC 25 nM and THC 0.25 nM groups. *p < 0.01 when compared with THC 25 nM, THC 2.5 nM, and THC 0.25 nM groups. #p < 0.05 when compared with THC 25 nMand THC 2.5 nM groups. Groups are: Ctrl, Control; M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2, THC 2.5 nM; T3, THC 0.25 nM,(F) Expression of tau following melatonin and THC treatment in N2a/A�PPswe cells. +p < 0.05 when compared with the THC 25 nM, THC 2.5 nM, and THC 0.25 nM groups. **p < 0.01 whencompared with the THC 25 nM, THC 2.5 nM, and THC 0.25 nM groups. #p < 0.05 when compared with THC 2.5 nM group. Groups are: Ctrl, Control; M1T2, 10−5 M Melatonin + 2.5 nM THC;M2T2, 10−6 M Melatonin + 2.5 nM THC; T1, THC 25 nM; T2, THC 2.5 nM; T3, THC 0.25 nM.
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(A) (B)
Fig. 9. (A) The enhancement of mitochondria function to cells treated with different: N2a/A�PPswe cells were cultured in 10 cm tissue cultureplate and then treated with drugs for 36 hours and mitochondria were harvested and tested for their ability of using oxygen utilization. Ctrl,Control; M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T2, THC 2.5 nM; M1, 10−5 M Melatonin, (B)The enhancement of mitochondria function to cells treated with different: N2a/A�PPswe cells were cultured in 10 cm tissue culture plate andthen treated with drugs for 36 hours and mitochondria were harvested and tested for their ability of using oxygen utilization. Ctrl, Control;M1T2, 10−5 M Melatonin + 2.5 nM THC; M2T2, 10−6 M Melatonin + 2.5 nM THC; T2, THC 2.5 nM; M1, 10−5 M Melatonin.
Table 1Difference and percent decrease of A�40 (pg/ml) in THC treatedcells at 2.5 �g/ml compared with the control at different time points
Time Point 6 h 24 h 48 h
Control 1064.025 5303 5935.525THC 2.5 �g/ml 965.827 3648.975 2894.175Percentage of decreased A�40 9.23% 31.19% 51.24%
shown that memory impairment was identified in rats458
treated with THC [42]. It should be clear, however,459
that the memory impairment observed occurred at con-460
centrations more than a thousand times higher than461
what is presented here as a beneficial treatment in AD462
model N2a/A�PPswe cells. The concentrations used463
in the study are considered to be extremely low, as464
the concentrations that we focused on in the study465
were from 2.5 nM of THC down to 0.25 nM of THC.466
Although some studies with ultra-low doses of THC467
have indicated neurotoxic roles [42], newer research468
shows a neuroprotective role and actually promotes469
elevation of phosphorylated cAMP response element-470
binding protein (pCREB) by increasing the levels of471
brain-derived neurotrophic factor in the frontal cortex472
[43]. Furthermore, the dosing used in our study is a473
lower concentration than that in the aforementioned474
research. Therefore, we believe that THC has a thera-475
peutic value, and that at low enough doses, the potential476
benefits strongly prevail over the risks associated with477
THC and memory impairment.478
In addition to the A� concentration suppression,479
benefits of THC, analyzed with a western blot and480